Hello, some smiths drill & tap set-screw through front of hanger to allow pressure adjustment under barrel..some have access hole running up at angle through forend screw hole. I have a std. wt. 26" brl. in .222 Rem. that will do 1/2-3/4" at 100yds . It seems the bigger calibers can be more sensitive. Also, you might check the quarter rib...mine was way out of wack when screws were loosened.